About a year ago, the US Army launched a program to find the best OTS (Off The Shelf) sound suppressor for the Army’s 9mm M9 pistol. About a dozen manufacturers submitted suppressors for the competition, with Advanced Armament sending five of theirs to Picatinny Arsenal for evaluation. The following discussion provides a look at these five suppressors as well as the Army’s performance criteria used to evaluate the competing designs.

Evolution-9
One might argue that this story really begins about two years earlier, when Picatinny Arsenal approached several manufacturers requesting suppressors that would cycle reliably on a GLOCK 19. A special operations group was the end-user stimulating this interest. Picatinny’s subsequent testing determined that none of the submitted cans would allow reliable cycling of the pistol. It took a while to sort out the problem. It turns out that several of the suppressor manufacturers recommended that a well-known maker of pistol barrels provide the extra-length barrels for the tests. These replacement barrels were all oversized and this caused the reliability problems. When Advanced Armament Corporation fitted threaded extensions to factory G19 barrels, the GLOCK pistols with AAC’s Evolution-9 sound suppressors cycled with 100 percent reliability.